For treatment against blood vessel dilation that is a disease of the artery or vein, as described in Non-Patent Document 1, there have been known a coil inserted into the blood vessel dilation, a stent inserted into a main blood vessel having the blood vessel dilation, and the like that are used in combination with a catheter, a balloon and the like.
As such a type of stent, there has conventionally been known a stent having a multiplicity of thin wires of elastic metal braided into a hoselike body with small interspaces provided between the wires, the hoselike body causing the individual thin wires to finely gather when pulled in the longitudinal direction and performing resilient restoration to the original hoselike body when released from pulling.
The conventional stent, however, has a defect in that sufficient blocking of blood flow from the blood vessel into the dilation cannot be achieved because of small interspaces opening between the thin wires of the stent once the stent that has been gathered finely by the pull in the longitudinal direction is inserted into the catheter, guided into the blood vessel, and pushed out of an extremity of the catheter in an area of development of the dilation so as to cause resilient restoration to the original hoselike state until the restored stent is set in a position such that the opening of the dilation is closed.
A stent having a multiplicity of thin wires of elastic metal arranged closely and braided into a hoselike body for improvement of blocking blood flow into the dilation has had a drawback of being prone to closing collateral vessels in the vicinity of a dilation even though it may be capable of blocking blood flow into the dilation when being guided likewise to an area of development of the dilation in a blood vessel and set in a position such that an opening of the dilation may be closed.
There has been proposed a stent in which a multiplicity of thin wires of elastic metal braided into a hoselike body with interspaces provided between the wires and in which a flexible synthetic resin film is stuck in a cylindrical shape on a portion of the hose having a length required for closure of an opening of dilation, whereas bulkiness of the synthetic resin film may make it impossible to insert the conventional stent in a bunched state into a microcatheter for guidance of the stent into a blood vessel.
As an art relating to the invention, an apparatus for forming an interknitted cord is disclosed in Patent Document 1. A mechanism obtained from improvement of an apparatus for manufacturing a plaited cord is used therein as an apparatus for forming a cord to be a base to attach a wig or an extension to a human head. The apparatus as described therein has a plurality of carriers attached with a bobbin and a mechanism to drive the carriers in a figure-of-8-like zigzag traveling route and performs action of knitting threads and interknitting hair by operating the carriers in a condition of extending the threads from the bobbin towards the head.    [NON-PATENT DOCUMENT 1]: Ryutaro Himeno “Bio-Mechanical Simulation at RIKEN, Current Status and its Future” (“NAGARE”, vol. 23, p 437-p 443 (2004))    [PATENT DOCUMENT 1]: JP 2008-57079 A